烈度仪记录与强震及测震记录的对比分析——以2015年河北昌黎M_L4.5地震为例
摘要
以2015年河北昌黎M_L4.5地震中测震、强震及烈度仪台站记录到的事件波形为研究对象,通过对比分析挑选的两组观测台站的记录波形以及不同台站的噪声记录特征,获得了烈度仪台站观测记录能力及特点的认识.结果表明:烈度仪台站产出的记录在部分频段(1—10Hz)与传统强震台站、测震台站均有较好的一致性,但在中长周期部分存在较大差异;在相同观测频带(0.1—10Hz)下,由烈度仪台站记录积分得到的速度时程、位移时程也与强震台站、测震台站的观测结果具有良好的相关性,说明烈度仪台站产出的加速度记录具有一定的可积分性;烈度仪台站记录的噪声水平远超出强震台站和测震台站,基本为仪器自噪声,不包含天然地脉动成分.此外,由于本研究所用的烈度仪采用了16位的A/D转换器,对震相到时的精确拾取产生了不利影响.综上,本文认为烈度仪台站较适用于中强地震的近场观测.
Based on seismic records of Changli M_L4.5earthquake in Hebei Province,by analyzing two groups of waveforms and comparing seismic noise characteristics of seismograph station,strong ground motion station and seismic intensity instrument(SII)station,this paper acquires basic understanding of each kind of these stations,especially the SII station,such as the ability to record micro-earthquakes.The results show that,in certain frequency band(1--10Hz),seismic waveforms are quite similar for both the SII station and the strong ground motion station or the seismograph station,but large differences appear in mid-long period part.For the same frequency band(0.1--10 Hz bandpass filtered),velocity history and displacement history that are integrated by the SII station data have good correlations and coherences with those from seismograph stations and strong ground motion stations,suggesting that the SII records have certain integrability to some extent.The noise levels of SII stations are far beyond seismograph stations and strong ground motion stations,normally are instrument noise without micro-tremor at all.As a result of only a16 bit A/D convertor applied,the precision of sampled data is limited and then the accuracy of seismic phase picking will be adversely affected.In conclusion,we think that SII stations are more suitable for moderate to large near-field earthquakes monitoring.
引文
金星,张红才,李军,韦永祥,马强.2012.地震预警震级确定方法研究[J].地震学报,34(5):593-610.Jin X,Zhang H C,Li J,Wei Y X,Ma Q.2012.Research on earthquake early warning magnitude estimate[J].ActaSeismologica Sinica,34(5):593-610(in Chinese).
李昌珑.2013.基于MEMS加速度传感器的地震烈度监测技术研究与实现[D].武汉:中国地震局地震研究所:18-39.Li C L.2013.Research and Achievement on Earthquake Intensity Monitoring Technology Based on MEMS Accelerome-ter[D].Wuhan:Institute of Seismology,China Earthquake Administration:18-39(in Chinese). 廖诗荣,陈绯雯.2008.应用概率密度函数方法自动处理地震台站勘选测试数据[J].华南地震,28(4):82-92.Liao S R,Chen F W.2008.Automated seismic noise processing for seismic site selection using probability density func-tions method[J].South China Journal of Seismology,28(4):82-92(in Chinese). 刘钢锋,朱威,邹彤,林强.2011.MEMS加速度传感器在强震观测中的应用[J].大地测量与地球动力学,31(增刊):168-170.Liu G F,Zhu W,Zou T,Lin Q.2011.Application of MEMS acceleration sensor to macroseism observation[J].Journal of Geodesy and Geodynamics,31(Suppl):168-170(in Chinese). 王浩,丁炜.2011.MEMS加速度计与传统地震加速度计的比较研究[J].大地测量与地球动力学,31(增刊II):93-95.Wang H,Ding W.2011.Comparison among MEMS accelerometer and traditional seismometer[J].Journal of Geodesyand Geodynamics,31(Suppl II):93-95(in Chinese). 许建华.2006.基于微型传感器的地震加速度监测系统技术研究[D].北京:中国地震局地球物理研究所:17-37.Xu J H.2006.The Engineering System for Detection Earthquake Acceleration Based on Micromachined Accelerometer[D].Beijing:Institute of Geophysics,China Earthquake Administration:17-37(in Chinese). 中国地震局.2015.仪器地震烈度计算(征求意见稿)[S/OL].[2016-05-16].http:∥www.cea.gov.cn/publish/dizhenj/465/539/20161115104509713440448/index.html.China Earthquake Administration.2015.Calculation of Instrumental Seismic Intensity(Draft for Soliciting Opinions)[S/OL].[2016-05-16].http:∥www.cea.gov.cn/publish/dizhenj/465/539/20161115104509713440448/index.html(in Chinese). Chen D Y,Hsiao N C,Wu Y M.2015a.The Earthworm based Earthquake Alarm Reporting system in Taiwan[J].Bull Seismol Soc Am,105(2A):568-579. Chen D Y,Wu Y M,Chin T L.2015b.Incorporating low-cost seismometers into the Central Weather Bureau seismic network for earthquake early warning in Taiwan[J].Terr Atmos Ocean Sci,26(5):503-513. Evans J R,Allen R M,Chung A I,Cochran E S,Guy R,Hellweg M,Lawrence J F.2014.Performance of several lowcost accelerometers[J].Seismol Res Lett,85(1):147-158. Geller R J,Takeuchi N.1995.A new method for computing highly accurate DSM synthetic seismograms[J].Geophys JInt,123(2):449-470. Holland A.2003.Earthquake data recorded by the MEMS accelerometer:Field testing in Idaho[J].Seismol Res Lett,74(1):20-26. Horiuchi S,Horiuchi Y,Yamamoto S,Nakamura H,Wu C J,Rydelek P A,Kachi M.2009.Home seismometer for earthquake early warning[J].Geophys Res Lett,36(5):L00B04.doi:10.1029/2008GL036572. Hsieh C Y,Chao W A,Wu Y M.2015.An examination of the threshold-based earthquake early warning approach using a low-cost seismic network[J].Seismol Res Lett,86(6):1664-1667. Jin X,Zhang H C,Li J,Wei Y X,Ma Q.2013.Earthquake magnitude estimation using theτcand Pdmethod for earthquake early warning systems[J].Earthquake Science,26(1):23-31. Lin T L,Wu Y M,Chen D Y,Hsiao N C,Chang C H.2011.Magnitude estimations in earthquake early warning for the2010Jiasian,Taiwan,earthquake[J].Seismol Res Lett,82(2):201-206. McNamara D E,Buland R P.2004.Ambient noise levels in the continental United States[J].Bull Seismol Soc Am,94(4):1517-1527. Peterson J.1993.Observations and Modeling of Seismic Background Noise[R].USGS Open File Report 93-322.Albuquerque,New Mexico:U.S.Department of Interior Geological Survey:322. Tasi C Y,Lin T L,Wu Y M.2015.Application of waveform stacking to low-cost local earthquake early warning arrays in Taiwan[J].Seismol Res Lett,86(6):1668-1673. Wu Y M,Zhao L.2006.Magnitude estimation using the first three seconds P-wave amplitude in earthquake early warning[J].Geophys Res Lett,33(16):L16312. Wu Y M,Yen H Y,Zhao L,Huang B S,Liang W T.2006.Magnitude determination using initial P waves:A singlestation approach[J].Geophys Res Lett,33(5):L05306. Wu Y M,Chen D Y,Lin T L,Hsieh C Y,Chin T L,Chang W Y,Li W S,Ker S H.2013.A high-density seismic network for earthquake early warning in Taiwan based on low cost sensors[J].Seismol Res Lett,84(6):1048-1054. Wu Y M.2014.Progress on development of an earthquake early warning system using low-cost sensors[J].Pure Appl Geophys,172(9):2343-2351.doi:10.1007/s00024-014-0933-5. Zhang H C,Jin X,Wei Y X,Li J,Kang L C,Wang S C,Huang L Z,Yu P Q.2016.An earthquake early warning system in Fujian,China[J].Bull Seismol Soc Am,106(2):755-765. |